Thermocouple lance and cartridge



Feb. 16, 1965 H. 1'. NEWMAN, JR

THERMOCOUPLE umcs AND CARTRIDGE Filed Aug. 18. 1960 United States Patent 3,169,41 Patented Feb. 16, 1965 3,169,401 THERMOCQUPLE LANCE AND CARTRIDGE Harold "Thomas Newman, In, Exeter, Pa., assignor to Universal Electronics Labs, Inc., West Wyoming, Pa., a corporation of Pennsylvania Filed Aug. 18, 1960, Ser. No. 50,417 2 Claims. (31. 73-359) This invention relates .to a thermocouple lance and cartridge therefor, and has as its primary object the provision of .an improved lance together with an expendable thermocouple cartridge which may be disposed of when its utilityis .finished.

.An important object of the invention is the provision of a thermocouple lance which may be employed in any suitable localitywhere a thermocouple is desired, as, for example, the measuring of the temperature of molten steel baths in openhearth furnaces or under similar circumstances, which is provided with an expendable cartridge which may be readily attached to the lance, and held securely in position during use but which may be readily and easily removed and replaced when desired or necessary.

An additional object of the invention is the provision of a device of this character wherein the parts are securely and firmly locked in electrical association, to provide a high degree of accuracy in measurement of temperatures or the like.

A further object of the invention is the provision of a device of this character which is sturdy and durable in construction, reliable and efiicient in operation, and relatively simple and inexpensive to manufacture, assemble, and utilize.

Still other objects will in part be obvious and in part be pointed out as the description of the invention proceeds, and shown in the accompanying drawing wherein there is disclosed a preferred embodiment of this inventive concept.

In the drawings:

FIGURE 1 is a perspective view of the assembled lance and cartridge showing the cartridge in position.

FIGURE 2 is an exploded perspective view of the lance and cartridge partially in section to show certain interior components thereof.

FIGURE 3 is an exploded perspective view showing the assembly end of the lance and showing a section through the expendable cartridge and a fragment of its protective sleeve.

FIGURE 4 is an enlarged sectional view taken substantially along the line 4-4 of FIG. 3 as viewed in the direction indicated by the arrows.

FIGURE 5 is a fragmentary view similar to a portion of FIG. 3 disclosing a modified form of construction.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Having reference now to the drawings in detail, the device of the instant invention comprises a thermocouple lance generally indicated at 10, which includes a pair of pipe sections 11a and 11b, which are connected centrally by a conventional pipe coupling 12. One of the sections 11a has secured thereto an elbow 13, to which is welded a strap type handle 14, for facility in handling, and from one end of which extends a conventional reducing bushing 15 through which a cable assembly 16 extends. The other end 11b of the device is provided with a connector assembly generally indicated at 17. This assembly comprises a sleeve 18 which is internally threaded to engage the exterior threads 19 of the end of pipe section 11b and which is provided with an annular groove 21 having a pair of spaced apart openings 22 therein. An internal shoulder 23 forms a seat for a ceramic or other heat resistant disc 24 which has projecting therefrom a male connector element 25 having a groove 26 and a head 27 at its other end. An insulating ring 28 separates the head 27 from the shank 25 to provide for an electrical connection in a known and conventional manner. The opposite end of the disc 24 is provided with electrical connector plates 29 and 30, to which are secured as by means of screws 31 the opposite wires 16a and 16b of the cable assembly 16. The disc 24 is provided with an annular groove 32 which is adapted to be aligned interiorly with the groove 21, and the parts are adapted to be held in related assembly by a snap ring33, the projecting ends 34 of which pass through the openings 22 and engage in the groove 32 to hold the parts against disassembly.

The expendable thermocouple cartridge of the instant invention consists of a cylindrical refractory member 40, which is provided with an interior opening 41 which contains spaced apart electrical contacts 42 and 43 of conventional type, which are separated by a block 44 of insulating material. Wires 45 and 46 extend from the contacts 42 and 43, respectively, into a thermocouple element 47, in the form of a U-shaped frangible member, which extends into a metal cap 48 having side openings 49 by means of which the thermocouple may be contacted by the fluid in which it is immersed.

A cardboard or similar sleeve 50 is fixedly secured to a shoulder 51 on the expendable thermocouple element, and in the use and operation of the device the sleeve with its associated thermocouple element is slipped over the tube 11b, with the male element 25-27 engaging the contacts 42-43 to provide an electrical connection with the cable assembly 16 which leads to a suitable measuring device of conventional sort.

When the thermocouple element has served its purpose it may be removed simply by grasping the sleeve 50 and disassembling the entire device, since the only securing means are afforded by the frictional engagement of the resilient contacts 42 and 43 with the members 25, 27, and the associated groove 26.

An additional element may be similarly positioned on the device when desired, and the assembly is ready for reuse.

A slightly modified form of male connector element is disclosed in FIG. 5, and comprises a sleeve 51 which is adapted to be secured to the threaded end 19 of pipe section 11 in a manner similar to that of sleeve 18. The sleeve contains an inner disc 52 provided with a male contact element 53 similar to the element 25, and connections 54 similar to connector members 29 and 30 to which the wires 16a and 16b are adapted to be attached. A shoulder similar to the shoulder 23 is positioned internally of the sleeve 51 to insure the proper positioning of the disc 52. In this modification the disc 52 is provided with a groove 55 substantially identical to the groove 32, which is adapted to be engaged by projections 56 on the ends of a pair of threaded set screw members 57, which engage in oppositely disposed threaded bores 53, and take the place of the spring clip 33 and its associated projections 34. The use and operation of this device is identical to that of the foregoing modification.

From the foregoing it will now be seen that there is herein provided an improved thermocouple lance and expendable cartridge therefor which accomplishes the objects of this invention, and others, including many advantages of great practical utility and commercial importance.

As many embodiments may be made of this inventive concept, and as many modifications may be made in the embodiment hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative, and not in a limiting sense.

I claim:

1. A thermocouple lance, comprising in combination, an elongated tubular member, a handle at one end of said member, an electrical fitting in the other end of said member, said electrical fitting comprising a cylindrical sleeve, a heat resistant disc secured in said sleeve, means connecting one side of said disc to an electrical measuring instrument, a centrally disposed longitudinally extending male connector element fixed to the other side of said disc, an expendable thermocouple assembly having a centrally disposed bore therein removably mounted in said electrical fitting, said male connector element extending into said bore in said thermocouple assembly, spaced electrical contacts in said bore in engagement with said male connector element to hold said thermocouple assembly in said cylindrical sleeve and place the thermocouple in electrical communication with said electrical measuring instrument, said cylindrical sleeve including portions defining a substantially centrally positioned exterior annular groove having a pair of spaced apart openings therein, the portions of said sleeve defining said annular groove providing a shoulder interiorly of said sleeve, said heat resistant disc seated within said shoulder, portions of said disc defining an annular groove therein, the pair of spaced openings in said cylindrical sleeve in alignment with the groove in said disc, and securing means extending through said openings in said sleeve into the annular groove in said disc.

2. A thermocouple lance as defined in claim 1 wherein said expendable thermocouple cartridge comprises a substantially cylindrical refractory member, said electrical contacts in the bore therein in spaced apart relation, wires extending from said contacts into the thermocouple, a cap having openings therein positioned over said thermocouple, said male connector element extending into said bore having portions defining a groove adjacent the free end thereof, and said electrical contacts engaged in said groove.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES Publication by Leeds and Northrup Co. folder number ND 4644643 (1) -158, date September 1958.

ISAAC LISANN, Primary Examiner. 

1. A THERMOCOUPLE LANCE, COMPRISING IN COMBINATION, AN ELONGATED TUBULAR MEMBER A HANDLE AT ONE END OF SAID MEMBER, AN ELECTRICAL FITTING IN THE OTHER END OF SAID MEMBER, SAID ELECTRICAL FITTING COMPRISING A CYLINDRICAL SLEEVE, A HEAT RESISTANT DISC SECURED IN SAID SLEEVE, MEANS CONNECTING ONE SIDE OF SAID DISC TO AN ELECTRICAL MEASURING INSTRUMENT, A CENTRALLY DISPOSED LONGITUDINALLY EXTENDING MALE CONNECTOR ELEMENT FIXED TO THE OTHER SIDE OF SIAD DISC, AN EXPENDABLE THERMOCOUPLE ASSEMBLY HAVING A CENTRALLY DISPOSED BORE THEREIN REMOVABLY MOUNTED IN SAID ELECTRICAL FITTING, SAID MALE CONNECTOR ELEMENT EXTENDING INTO SAID BORE IN SAID THERMOCOUPLE ASSEMBLY, SPAED ELECTRICAL CONTACTS IN SAID BORE IN ENGAGEMENT WITH SAID MALE CONNECTOR ELEMENT TO HOLD SAID THERMOCOUPLE ASSEMBLY IN SAID CYLINDRICAL SLEEVE AND PLACE THE THERMOCOUPLE IN ELECTRICAL COMMUNICATION WITH SAID ELECTRICAL MEASURING INSTRUMENT, SAID CYLINDRICAL SLEEVE INCLUDING PORTIONS DEFINING A SUBSTANTIALLY CENTRALLY POSITIONED EXTERIOR ANNULAR GROOVE HAVING A PAIR OF SPACED APART OPENINGS THEREIN, THE PORTIONS OF SAID SLEEVE DEFINING SAID ANNULAR GROOVE PROVIDING A SHOULDER INTERIORLY OF SAID SLEEVE, SAID HEAT RESISTANT DISC SEATED WITHIN SAID SHOULDER, PORTIONS OF SAID DISC DEFINING AN ANNULAR GROOVE THEREIN, THE PAIR OF SPACED OPENINGS IN SAID CYLINDRICAL SLEEVE IN ALIGNMENT WITH THE GROOVE IN SAID DISC, AND SECURING MEANS EXTENDING THROUGH SAID OPENINGS IN SAID SLEEVE INTO THE ANNULAR GROOVE IN SAID DISC. 